/Engine/Source/Runtime/Engine/Classes/Engine/World.h
Trace a ray against the world using a specific channel and return the first blocking hit
TRUE if a blocking hit is found
bool LineTraceSingleByChannel ( struct [FHitResult](API\Runtime\Engine\Engine\FHitResult) & OutHit, const FVector & Start, const FVector & End, ECollisionChannel TraceChannel, const [FCollisionQueryParams](API\Runtime\Engine\FCollisionQueryParams) & Params, const [FCollisionResponseParams](API\Runtime\Engine\FCollisionResponseParams) & ResponseParam ) const